Automatic gun.



H. H. C. D U N WOODY.

AUTOMATIC GUN.

APPLICATION FILED APR. l 4. |91 1.

Patented May 29,1917.

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A Y! w -.--1 .--Wu i i -e a. siiimm l l l l V f n Gfbtouwsf UNITED STATES PATENT OFFICE.

HENRY C. DUNWOODY, OF WASHINGTON, DISTRICT 0F COLUMBIA, ASSIGNOR T0 DUNWOODY AUTOMATIC GUN AND PROJECTILE COMPANY, A CORPORATION 0F DELAWARE.

AUTOMATIC GUN.

Speeication of Letters Patent.

Patented May 29, 1917.

To all 'whom 'it may concern:

Be it lmown that I, HENRY H. C. DUN- WooDY, brigadier general U. S. Army, retired, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Automatic Guns; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to means for cooling gun barrels especially adapted for the cooling of the barrels of rapid fire guns and has for its object to provide a means which Vwill be simple in construction, eiiicient in action and comparatively inexpensive to manufacture.

Figure 1 is a diagrammatic side elevational view of a gun of the rapid fire type provided with this invention;

Fig. 2 is a longitudinal sectional view of a ortion of the barrel and its cooling means .il ustrated in Fig. 1;

Fig. 3 is a cross sectional view taken on the line 3--3 of Fig. 2, looking in the direction of the arrows; and

Fig. 4 is a diagrammatic enlarged plan view illustrating a portion of the serrated or roughened edges with which the cooling disks are provided.

1 indicates the breech portion of a gun of any desiredvv type, 2 the trigger thereof, 3 any desired rear sight, 4 any desired front si ht, and 5 a casing surrounding the barre 6. Said casing 5 is larger in diameter than is the barrel 6 and is spaced from said barrel by a plurality of disk-shaped members 7 These said disk-shaped members are preferably of the shape shown bem provided with an outer flange 8 fitting t e interior ofthe casing 5, and with an inner flange 9 adapted to be tightly driven onor welded to the barrel 6 in order to provide a good heat conducting joint.

Each of the members 7 are provided with a plurality of openings 10, four being illus trated in Fig. 3, to provide four radially disposed spokes or connections 11. Each of the openings 10 are serrated or roughened around their edges as shown at 12 to provide a plurality of sharp projections 13, best illustrated in Fig. 4.

The disks 7 are so disposed between the barrel 6 and the casing 5 as to cause the spokes 11 of the one disk to be angularly displaced with reference to the spokes of a succeeding disk. For` example, if four openings 10 are provided 1n each disk 'as shown, I prefer to displace the spokes of each4 succeeding disk through an angle of 3.0 degrees thus causing the longitudinal channels, formed by successive openings 10, to be obstructed or broken up by the succeeding spokes of succeeding disks. This disposition of the disks will be rendered clear if we consider Figs. 2 and 3. That is to say, supposing the spokes 11 of the disk Tthere shownto be disposed as indicated in Fi 2, and that the eye is directed along the arrel in the direction of the' arrows, the spokes of the next disk in this case would not appear because the disk that would ordinarily come next to the first disk 7 has been omitted so that the empty spaces 22 would appear in Fig. 3.

The eye, however, would catch the third disk 21 and its spokes 20 would appear to overlap the spokes 11 all as is illustrated in Fig. 3. However, it` is clear that if the omitted disks were in place that the' entire v area of the spaces 10 would be taken up by angularly displaced spokes. In other words, should the eye be directed in a direction opposite to that of the arrows in Fig. 2, it would successively see the `angularl displaced spokes 24 and 25, and would a so see the spokes of the third disk 26 lfilling up what corresponds to the empty spaces 22 in Fig. 3.

The effect of thus angularly displacin the spokes of the various disks is, as a ove stated, to break up what would otherwise be a continuous passage of air through the holes 10 and to therefore cause the air traversing the interior of the casing 5 to follow a zig-zag course around the outer edges of the various spokes. The passage of the ail' is thus obstructed by eachsucco sive spoke along the barrel and the nir is forced to impinge with a greater or less force against edges of said spokes with the result that it more efficiently strips the said spokes of their heat as will appear more fully below.

The barrel 6 is made somewhat longer than is usual and its extreme outer portion 30 is provided with a plurality of inclined passages 31, as shown, through which the gases of the explosion pass, and thus suck out the air filling the space 32 between the casing 5 and the barrel 6. As said air is thus sucked out of the space 32, additional air enters through the openings 33 with which the casing is provided at or near the rear end of the barrel, and thus there is effected a sort of pumping action which causes the air' to circulate freely through the openings 10 and around the edges of the individual spokesvof the disks. As'a matter of fact, as the bullet passes the first series of openings 31 the gases escape through said openings and set -up a vacuum in the space 32 between the casing and the barrel. A very brief interval after this vacuum is formed another vacuum is formed by. the bullet paing the second series of openings 31 and so on until the bullet has emerged at the muzzle 34. The effect of thus creating sufficient vacuums after very brief intervals of time in the space between the barrel and casing is tostart the air flowing through the tortuous passages between the spokes and to cause the same to finally pass out around the muzzle `34:, thus cooling the barrel.

Referring more particularly to Fig. 4, the serrations or very fine points 13 of the openings 10 in each disk accumulate heat thereon in the manner Well known. That is to say,

it is a well known principle of physics that heat accumulates on points to much higher densities than on fiat surfaces and that therefore it may be removed from said points with greater facility than it is from fiat surfaces. In other words, if the dotted lines 40 in Fig. 4 represent in a rough sort of way the densities of the heat accumulated on the various points 13, then it is evident that the air-passing along the outside barrel 6 will strip orpconduct olf or deprive the spokes 11 of their Iheat much more readily when the said openings 10 are provided with the points 13 than would be the case if the edges of said openings-were smooth. Inaddition to the above, it is further well known that when air passes along a smooth surface it sticks to the walls of the passage through thc action of the phenomena known as adsorption so that the air in the middle of the passages docs not accumulate as much heat as would be the case were the passages broken up and were thel air in the middle of the passages thus forced to contact with the walls of said passages. It is for this reason that radiators in general often cause thc the serrated or roughened' may vary aar/,sev

with the metal than is the case with straight passages.

It will thus be observed that by angu? larly displacing the spokes of the various disks 7 in the manner disclosed I rovide zig-zag or broken passages for the air, thus causingl a more intimate contact between the metal and the air than would otherwise be the case, and I further provide a longer contact between the air and the metal than would be the case with a straight passage. Further, by roughening the surfaces of the openin between the spokes of the different di s, I enable the air to more eifectually strip the heat from said disks than would otherwise be the case. In order that there'may be as much heat as possible conducted from the barrel Vto the various disks I preferably either braze or solder the sai disks to the barrel or else I autogenously weld or electrically weld them thereto thus makin them an integral part of the barrel. he outer casing may or may not be roughened as desired. If it is roughened as is usually done, of course, it will radiate heat to better advantage than if it is smooth. At 50 I have indicated the usual vent through which a portion of the gases may pass in order to operate the piston 51 located in the cylinder 53. The said piston 51 is returned by any suitable mechanism not shown and it operates any suitable or desired type of automatic loading mechanism aportion of which is indicated at 52.

It is obvious that those skilled in the art the details of construction as well as the arrangement of parts without departmg therefore I do not wish to be limited to the above description except as may be required by the claims.

What I claim is 1. In a rapid ire gun the combination of a gun barrel; a casing surroundin the same; means to admit air at one end o said casing; means to create a partial vacuum at the other end of said caslng; and a plurality of disk like members provided with staggered opnings for the passage of said air located tween said casmg and barrel, substantially as described.

2. In a rapid fire gun the combination of a gun barrel; a casing surrounding the same; means to admit air at one end of said casing; meansV to create a partial vacuum at thc other end of said caslng; and a plurality of disk like members provided with openings having edges provided with profrom the spirit of the invention andections for the passage of said air located etween said casing and barrel, substantially as described.

3. In a rapid fire gun the combination of a gun barrel; a casing surrounding the same provided with means to admit air at one end of said casing; means to create a partial vacuum at the other end of said casing; and

a plurality of disk like members provided to create a partial vacuum at the other end of said casing; and a plurality of disk like members provided wlth openings having projections on their edges for the passage of said air located between said casing and barrel, substantially as described.

5. In a rapid fire gun the combination of abarrel provided with a muzzle portion, having a plurality of perforations through which the gases of explosion may pass; a casing surrounding said barrel and perforations; a plurality of disks integral with said barrel located between said barrel and casing each disk provided with a plurality of openings and each opening being angularly d1sposed with relation to an adjacent opening to form a tortuous peassage for said air; su stantially as descri d.

In testimony whereof I aix my signature.

HENRY H. o. DUNwooDY. 

